1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
#include <assert.h>

#include "cg.h"
#include "comment.h"
#include "error.h"
#include "expected.h"
#include "parsedirective.h"
#include "parseexpr.h"
#include "symtab.h"
#include "warning.h"

bool
parseDirective(void)
{
    if (token.kind < DIRECTIVE_FIRST || token.kind >= DIRECTIVE_END) {
        return false;
    }
    commentClear();
    commentAddCurrentToken();
    enum TokenKind directive = token.kind;
    getToken();
    switch (directive) {
        case DOT_TEXT:
            commentClear();
            cgSetActiveSegment(CGSEG_TEXT);
            break;
        case DOT_DATA:
            commentClear();
            cgSetActiveSegment(CGSEG_DATA);
            break;
        case DOT_BSS:
            commentClear();
            cgSetActiveSegment(CGSEG_BSS);
            break;
        case DOT_STRING:
            expected(STRING_LITERAL);
            cgAppendString(token.processedVal.cstr);
            commentAddCStr("\"");
            commentAddCStr(token.val.cstr);
            commentAddCStr("\"");
            getToken();
            break;
        case DOT_BYTE:
        case DOT_WORD:
        case DOT_LONG:
        case DOT_QUAD: {
            size_t numBytes = 0;
            switch (directive) {
                case DOT_BYTE:
                    numBytes = 1;
                    break;
                case DOT_WORD:
                    numBytes = 2;
                    break;
                case DOT_LONG:
                    numBytes = 4;
                    break;
                case DOT_QUAD:
                    numBytes = 8;
                    break;
                default:
                    assert(0);
            }
            struct Expr *expr = parseExpression();
            /*
            if (!expr) {
                error("expression expected. Got '%s'\n",
                      strTokenKind(token.kind));
            }
            */
            cgAppendInteger(numBytes, expr);
            commentAddExpr(expr);
        } break;
        case DOT_ALIGN: {
            commentClear();
            struct Expr *expr = parseExpression();
            if (expr) {
                uint64_t val = evalExpr(expr);
                if (typeExpr(expr) == UNKNOWN) {
                    errorAt(locExpr(expr), "can not resolve expr");
                }
                cgAlign(val);
            } else {
                warning("alignment directive with no operand is ignored\n");
            }
        } break;
        case DOT_SPACE: {
            struct Expr *expr = parseExpression();
            if (!expr) {
                error("expression expected. Got '%s'\n",
                      strTokenKind(token.kind));
            }
            uint64_t val = evalExpr(expr);
            if (typeExpr(expr) == UNKNOWN) {
                errorAt(locExpr(expr), "can not resolve expr");
            }
            cgAppendSpace(val);
        } break;
        case DOT_GLOBL:
        case DOT_GLOBAL: {
            commentClear();
            expected(IDENT);
            const struct UStr *ident = makeUStr(token.val.cstr);
            getToken();
            symtabGlobal(ident);
        } break;
        case DOT_EQU: {
            commentClear();
            expected(IDENT);
            const struct UStr *ident = makeUStr(token.val.cstr);
            getToken();
            expected(COMMA);
            getToken();
            struct Expr *expr = parseExpression();
            if (!expr) {
                error("expression expected. Got '%s'\n",
                      strTokenKind(token.kind));
            }
            symtabSet(ident, expr);
        } break;
        default:
            assert(0);
            return false; // never reached
    }
    cgAppendComment(commentGetCStr());
    expected(EOL);
    getToken();
    return true;
}